Turbofan gas turbine engine fan blades suffer from high cycle fatigue, produced by high cycle vibrations, which significantly affects the performance and life of the fan blade.
Our published UK patent application GB2371095A discloses a turbomachine blade with a hollow interior and a viscoelastic vibration damping material is provided within the hollow interior of the turbomachine blade to damp vibrations of the turbomachine blade. However, it is difficult to inject the viscoelastic material into the hollow interior of the turbomachine blade, the viscoelastic material only damps vibrations over a limited temperature range, the viscoelastic material is not load bearing and the viscoelastic material may not withstand heat treatments required to manufacture a turbomachine rotor with integral hollow turbomachine blades.